Most vehicles with a conventional powertrain are designed to accelerate slowly from a stopped position when they are idling in gear and the driver releases the brake pedal. The torque that causes this slow acceleration is provided by the powertrain and is sometimes referred to as “creep torque,” as it generally causes the vehicle to creep forward from a stopped position, even when the driver is not engaging the accelerator pedal. If the vehicle is at a traffic light, for example, the driver can overcome the creep torque and maintain the vehicle in a stationary position by engaging the brakes. When the brake torque exerted by the vehicle brakes exceeds the creep torque supplied by the powertrain, the vehicle remains stationary; when the creep torque exceeds the brake torque, the vehicle moves forward.
Providing creep torque in a vehicle with a conventional powertrain—for example, one having an internal combustion engine, an automatic transmission and a torque converter—is relatively easy since the internal combustion engine is usually idling, even when the vehicle is stationary. Vehicles with electric powertrains, however, do not operate in the same manner. In order to simulate the driving experience of a traditional vehicle, hybrid electric vehicles (HEVs) and other vehicles with electric powertrains sometimes supply a creep torque that mimics that of a conventional powertrain. However, supplying creep torque in an electric powertrain without any control mechanisms in place can unnecessarily consume energy and reduce the overall efficiency of the vehicle.